Moving sidewalk



I Fb. 3, 1970 w. KARRl y3,493,097

' i MOVING SIDEVWALK Original Filed Aug. 8, 1966 NvENToR Y WILLIS F.KARR Mwz:

ATTORNIE YS Feb. 3,1970' W.`F.\K, \IRR4 1 v 3,493,097

MOVING SIDEWLK original FiledAug. 196e i 4 sheets-sheer 2 W f w Y NV- 4Y) t', U i? I s e? N v Q LL. Q LL INVIENTOR ATTORNEYS Feb. s, 1970 Lw,F. ARR 3,493,091

original Filed Aug. 9, 199e MOVING 'SIDEWALK 4 Sheets-Sheet 5 mvENToRWILLIS F, ARR

ATTORNEYS /MMWZM W. F. KARR MOVING SIDEWALK Feb. 3, 1970 4 Sheena-sheet4;

Original Filed Aug. 1, 196

FIG. I I

/ IIIIIIIIIj222 FIG. I 2

INVENTOR WILLIS F, KARR Mv/Ml ATTORNEYS United States Patent O U.S. Cl.198-181 7 Claims ABSTRACT OF THE DISCLOSURE The broad aspect of theinvention consists in the provision of a plurality of pallets formedwith planar upper surfaces having one edge of the surface formed in aconcave circular arc and an opposed edge formed in a convex circular arcwith connecting links joining adjacent pallets into a chain with theconvex edge of one abutting the concave edge of the next. The linksjoining adjacent pallets are pivoted at one end at the center of theconvex edge of the one of the pallets so as to restrain the motion ofthe pallet next adjacent on the convex side, in the plane of the planarsurface, to a pivoting motion about center of the convex edge. Thismaintains pallets in contiguous relation while following a non linearcourse.

This is a division of Ser. No. 570,957 filed Aug. 8, 1966, now PatentNo. 3,399,758 issued Sept. 3, 1968.

This invention relates to conveyors having planar horizontal uppersurfaces adapted to transport persons and materials between spacedpoints.

A further aspect of the invention relates to a rst pallet configurationwhich provides a hinge extending transversely across the width of thepallets, normally to their general direction of motion, which allows thepallets to bend in directions perpendicular their motion so as toformreturn bend. Another aspect of the invention lies in the provisionof linkages which allow various pallets to assume different horizontallevels with respect to one another, in the manner of an escalator, whilestill maintaining their contiguous relationship.

A still further aspect of novelty is the provision of a palletsupporting configuration employing rollers which are resilientlyretained to provide a cushioning support for the pallets. An alternativesupport system utilizes a plurality of belts which are arrayed in shortsegments along the course of motion and support the pallets on theirlower surfaces to also provide a cushioned travel.

The driving systems for the pallets along the courses established by therollers or the belts may take either of two novel forms. In one, each ofthe pallets has a cam follower disposed below and depending from one ofits sides, and along one point of the course such follower makesthreading engagement with a screw which lies parallel to the directionof the motion of the pallets at that point, to provide the drivingimpulse. In an alternative embodiment of the driving system each of thepallets has a cam follower disposed from the center of its bottom sideand the screw is disposed below and parallel to a section of the lengthof the conveyor so as to contact and mesh with the cam followers as theypass that point and drive them along.

Another aspect of novelty is in the provision of such conveyors in shortclosed loop segments which provide a forward and return motion path, aplurality of such segments being joined by Hat, stationary platformswhich allow persons moving along the conveyor to walk between them onthe platforms which also provide crosswalks.

Ffice These and other areas of novelty, objects, advantages andapplications will be made apparent by the following detailed descriptionof various preferred embodiments of the invention. The descriptions makereference to the accompanying drawings in which:

FIGURE 1 is a perspective view of a plurality of conveyor sectionsformed in accordance with a rst embodiment of the invention, providing aplurality of paths for transporting persons;

FIGURE 2 is a perspective view of the underside of a pair of palletsused in connection with the embodiment of FIGURE 1;

FIGURE 3 is a plan view of the return bend of one of the conveyorsections of FIGURE 1, with the stationary platform removed;

FIGURE 4 is a transverse sectional View through one of the conveyorcourses, taken along line 4 4 of FIG- URE 3;

FIGURE 5 is an end view of a vertical return bend which a conveyorformed in accordance with FIGURE l is capable of undergoing;

FIGURE 6 is an elevational view through the drive mechanism of a secondembodiment of the invention;

FIGURE 7 is an end View of the drive system of the embodiment of FIGURE6, taken along line 7 7 of FIGURE 6;

FIGURE 8 is a perspective view of the details of one of the rollersupports employed in the embodiment of FIGURE 6;

FIGURE 9 is a plan view of the pallet support system forming a thirdembodiment of the invention;

FIGURE 10 is a transverse sectional view taken along line 10-10 ofFIGURE 9;

FIGURE 11 is a side view of a fourth embodiment of the inventionrepresenting a form of pallet which is capable of undergoing escalatortype of operation; and

FIGURE 12 is a top view of the pallet shown in FIG- URE 11.

Referring to the drawings a first embodiment of the invention is builtabout a plurality of pallets, parts of which are shown inverted inFIGURE 2 and top View in FIGURES 1 and 3. Each pellet is formed in twoparts. One, generally indicated at 20 is formed of a flat plate having asemi-circular convex edge 22. The semi-circular edge preferably consistsof a arc and its two edges merge tangentially with short straight sides24. The line between the straight sides, forming one edge of the palletsection 20, is joined by an elongated hinge member 26 to a second palletsection generally illustrated at 28. The section 28 has one straightedge 30 joined by the hinge 26 to the section 20, a pair of straightsides 32 which extend normally to the edge 26, and a concavesemi-circular arc 34 which connects the two edges 32.

A three-sided, equilateral frame member 36 is fixed to the underside ofthe section 28 so that one of its apexes projects symmetrically acrossthe concave arc 34. This projecting apex has a central hole 38 which isadapted to slide over a pin 40 projecting downwardly from the undersideof the section 20 at the center of the convex edge 22. A pair of rollers42 are rotatably supported in projections 44 which are joined to thetriangular link members 36 and on the members 28, and they are adaptedto roll about axes which form radial lines to the concave arc 34. Thesurfaces of the rollers 42 project upwardly from their supports 44, andwhen the hole 38 on the apex of one of the triangular arms 36 is passedover the pin 40 on the adjacent section 26, the upper sides of theroller abut the underside of the member 26.

The proportions of the members are such that when in this relation theconvex edge 22 of the section 26 is in immediate proximity to theconcave edge 34 of one of the sections 28 and the rollers 42, and thepins 40 allow one of the sections to pivot with respect to one anotherin the plane of their surfaces. The hinges 26 allow the two sections 20and 28 to bend with respect to one another about the axis of the hinge.

It may be seen that a plurality of the sections 20 and 28 may be joinedtogether by the arms 36 and the hinges 26 to form a closed loop. Thisloop may either be bent about an axis vertical to the surfaces of thepallets, as shown in FIGURE 3, to form return bends, or it may be Ibentabout an axis parallel to the surfaces of the pallet, and to the hinge26, in the manner shown in FIGURE 5. When bent as shown in FIGURE 5 thepallet surfaces bend with respect to one another at the hinges 26 asthey traverse the return section. When a bend in the nature of FIGURE 3is employed the pallet surfaces are always horizontal. In FIGURE 3 iscan be seen that when the sections 20 and 28 bend with respect to oneanother no gap is formed between adjacent pallets because of therotation of the concave edge 34 with respect to the convex edge 22.

The lower ends of the pins 40 project through the holes 38 in the apexin triangular member 36 and rotatably support rollers which thus projectbelow the lowest point on the pallet.

The pallets are completed by downwardly projecting inclined plates 52which project from one of the edges 32 of the sections 28 at inclinedangles and rotatably support bearing drive members 54.

The closed chains of pallets thus formed may be supported and driven ina number of ways. In the rst embodiment, as best seen in FIGURE 4, thetrack which the chain of pallets follows employs a pair of side uprightsupport members 60 and 62 extending parallel to one another along thecourse. The outer edges of members 60 and 62 are separated from oneanother transversely by the width of the pallet section. The side edgesof the pallets thus rest on the top of the members 60 and 62. Channels64 and 66 are formed downwardly from the upper side of the members 60and 62 and pressurized air is maintained in the channels by suitableblower members 68 and 70 which are disposed on the sides of the trackand communicate with the channels through ducts 72 and 74 respectively.The pressure of the air in the channels 64 and 66 is maintainedsuiciently high as to create an air bearing surface between the loweredges and the outer sides of the pallets and the support members 60 and62. This bearing minimizes the friction between the elements and thedriving forces required to move the pallets along their course.

A center guide member 76 is supported midway between the inner and outersupports 60 and 62 and is channel shaped in cross section with upwardlydirected flanges. The guide channel 76 extends along the entire conveyorcourse between the side supports 60 and 62. The roller guide 50 of eachof the pallets extends down into the upper open end of the channel 76and makes a loose t therewith. The sides of the channel thus restrainthe motion of the pallets in their plane, and guide them along thecourse. The channel 76 thus guides the pallets, and the air bearingsupports 60 and 62 provide an upward force which retains any weightsupported on the pallets.

The drive system for the pallets disclosed in FIGURES 3 and 4 consistsof an elongated screw 80 having a square thread, which is rotatablysupported parallel to the conveyor path at the interior side of thepallet course, along one straightaway section. The screw is rotatablyjournaled in bearing blocks 82 and 84 and is driven by an electric motor86 through a belt drive 88. The screw engages the cam followers 54,associated with each of the pallet sections 28, as they move into thearea of the screw. The screw is long enough to engage the cam followers54 on three pallets simultaneously. These pallets push the pallets aheadof them and pull the pallets behind them to drive the entire pallettrain over the course.

The far end of the screw 84 drives a second belt 90 which powers a rightangle drive 92 having a vertical shaft. This shaft rotates suitablemechanism (not shown) for driving a handrail 94 in timed relation to themotion of the conveyor. The handrail is disposed adjacent to the upperedge of an elongated raised section 96 which extends between the twosides of the conveyor in the straightaway section and projects upwardlyfrom them to form a separation between the two. The top of the raisedsection 96 is approximately waist high and the handrail 94 is formed ofa resilient elongated extrusion and supported on the upper edge of therail. The raised section 96 might be formed with transparent sectionsacting as display windows for various articles.

The conveyor sections are arranged in a plurality of courses and areseparated by flat platforms 100 which cover the return sections andprovide access between various conveyors. The platforms 100 areconnected to the ground level by ramps 102 which allow the platforms tobe used as cross walks or to gain access to and from the conveyorsections.

FIGURE 5 illustrates an alternative form of conveyor constructionwherein the return bend is made about a horizontal axis so that theconveyor section returns in an inverted manner and only the uppersection is useful for transport. Rather than being supported from theguides 60 and 62, the conveyor FIGURE 5 is supported on a plurality ofbelts 108 which are arrayed over rollers 110 in a staggered fashion. Oneside of the lbelt between the rollers supports the conveyor. The rollersat the end section are disposed so as to cause the belts to form a loopin a vertical plane about a horizontal axis. As the conveyor sectionspass over this return section they bend about the hinges 26. Any of thedisclosed forms of drive and guide means may be employed with thisembodiment.

An alternative form of drive and support system is illustrated inFIGURES 6, 7 and 8. The pallets employed with this embodiment areidentical to those illustrated in FIGURE 2 except that they do not havethe cam followers 54 or their sup-porting projections 52. Rather, thepallets are driven by the cam followers 50 which also act as guides.

As seen in FIGURE 6 the pallets employed with the embodiments of FIGURES6, 7 and 8 does not utilize hinges but are rather constructive in singlesections and joined together by straight link arms, fixed to a palletsection and projecting over its concave edge. The other end of the armconnects to a pin 124 which projects downwardly from the center of theconvex section. Pin 124 carries a cam follower 12S on its lower edgewhich serves as a guide of the adjacent pallet and drive element. Thepallets 120 have flat undersurfaces and they are supported by two seriesof rollers and 132 which arev arrayed in two rows under the inner andouter sides of the pallets along the course of the conveyor and arerotatably supported about axes which project transversely to theconveyor course.

As is best seen in FIGURE 8 the rollers 130 are supported on shafts 134by means of ball bearings 136. Each of the shaft ends projects outwardlyof the roller and is retained in a hard rubber block 138. The blocks 138have slots 140 which allows them to be removably inverted in grooves 142formed at regular intervals in pairs of rails 144 and 146 which extendalong the conveyor course. Two sets of rails are employed, onesupporting the rollers 130 and the other supporting the rollers 132. Therails 144 and 146 are supported by cross elements 148 which projecttransversely to the conveyor course at regular intervals and areretained on a base member 150.

The rubber blocks allow individual roller members 130 and 132 to bereplaced and also insulate the pallet from the supporting base 150 toprovide a cushioned ride.

The base member 150 has a pair of upwardly projecting flanges 152 onopposed sides with inwardly directed lips 154 which `extend above theopposed edges of the pallets to prevent any gaps from opening betweenthe pallets and the supporting structure.

The drive system for the embodiment of FIGURES 6, 7 and 8 employs anelongated screw 160 having square threads which is supported within thebase 150 centrally under the pallets and parallel to the conveyorcourse. Screw 160 is supported on a pair of end bearing blocks 162 and164. It is rotated by a belt 166 from a drive motor 168 located on oneside of the conveyor. The threads of the screw 160 mesh with the camfollower 126 as they pass over the screw area and -provide the unit withthe necessary driving impulses. Appropriate guide means (not shown)engage the cam followers 126 in the areas other than that which thescrew 160 is contained, to limit its sideward motion.

Another support and driving system is illustrated in FIGURES 9 and 10.In this embodiment, which may employ belts ofV the same type illustratedin the embodiment of FIGURES 6, 7 and 8, the pallets 19t) are connectedby rigid links 192 and have downwardly projecting guide rollers 194. Theguide rollers are aligned within central guiding channels 196 havingopen ends, for purposes of transverse alignment along the conveyorcourse. The pallet surfaces are supported on a plurality of belts 198which are arrayed on pulleys 200 supported on rotatable shafts 202 whichproject transversely across the conveyor course at regular intervals.The belts are staggered with respect to one another, and a belt may bearrayed over a series of pulleys to provide a relatively continuous beltsurface for the support of the pallet undersides. One or more of theshafts 202 along the conveyor courses are p-owered by motor drivesystems 206, located to one side of the conveyor course. The drivesystem rotates the pulleys associated with a particular powered shaftand thus rotates the belts. The motion of the belts is transferred tothe 4pallets driving them along their course. Thus the belts act as botha support and a drive system for the pallets.

The embodiment of the invention illustrated in FIG- URES 1l and l2 iscapable of moving along upward and downward inclines, either in astraight line or in a curved configuration, while still maintaining thepallet surfaces parallel to one another, much in the manner of anescalator. `Since the pallets may move both at an incline and curve,they may be formed into a wide variety of configurations, includingspirals.

The pallets employed in this embodiment have flat upper surfaces 220with forward semi-circular convex edges 2.22 and rear semi-circularconcave edges 224. Straight sides 226 join the rearmost portion of theconvex arc to the edge of the concave arc. Rather than being formed in athin, sheet-like configuration, the 4pallets of the present inventionhave sides which extend normally to the upper surface 220 for depth atleast equal to the vertical separation which the surfaces of the palletswill undergo while traversing an incline.

Two side legs 228 and 230 project downwardly from the underside adjacentto opposed sides of the convex surface 228. They have wheels 232 and 234at their lower edges which ride in support tracks 236 and 238respectively. These tracks extend along the length of the conveyorcourse, lparallel to one another, and provide essentially verticalsupport to the pallet, as will be subsequently described. Each of thepallets also has a downwardly extending central leg 240 which is of thesame length as the legs 228 and 230 and has a wheel 242 which is of thesame length as the legs 228 and 230 and has a wheel 242 supported on itslower edge. This wheel 242 is supported in a central track 244 whichruns midway between the two side support rails 236 and 238.

Thus, each pallet is provided with a three point suspension on thetracks 236, 238 and 244. When the pallets are moving along a horizontalline these three tracks are at the same level, as is shown to the rightin FIGURE 11. However, when the pallets must move along an incline, sothat their upper surfaces are displaced with respect to one another, thetwo outer tracks 236 and 238 must be displaced with respect to thecentral track 244. At the left of FIGURE ll it will be seen that theouter tracks 236 and 238 are elevated with respect to the central track244, so that the pallet upper surface remains horizontal whiletraversing the grade,

The pallets are joined to one another by link arms 250 which must becapable of pivoting with respect to both of the pallets in thehorizontal plane, must be capable of pivotation in the vertical plane,yand must be capable of changing the effective length between theirconnecting points on the legs 240 of adjacent pallets, as they movebetween an incline or a horizontal course. In order to achieve this thelinks are joined to one of the arms 240 by members 252 which are capableof pivoting in the horizontal plane and by links 254 which may pivot inthe vertical plane. At their other end they are connected to theadjacent arm 240 by pivot elements 256 which are also capable ofpivoting in the horizontal plane. Intermediate these two connections 254and 256 they have carry cam support members 258. The members 258 areattached to the arms 250 and to the pivot members 256 by pin connection260 which allow them to pivot in vertical plane.

The members 258 have downwardly projecting rollers 262 which ride afourth track 264 that rims immediately adjacent to the center track 244,and act to modify the effective length of the link members 250 betweentheir necessary distance when the pallets are moving horizontally and onthe incline. As seen in FIGURE 11 when the pallets are moving along anincline, at their maximum inclination with respect to one another, thelinks 250 must extend the maximum distance between their connectionswith two adjacent pallets. Accordingly, the track 264 is so aligned withrespect to its adjacent track 244 that the members 258 provide themaximum length to links 250. When the pallets are moving in thehorizontal, the effective distance of the links must be shortened.Accordingly, the rail 264 assumes the same level as the rails 244 themembers 258 become cocked as seen to the right in FIGURE 11, effectivelyshortening the links 250.

Having thus described my invention, I claim:

1. a conveyor of the type described, comprising:

a plurality of pallets each having llat upper surfaces,

a first semi-circular convex edge and an opposed semi-circular concaveedge;

link members connecting the center of the convex edge of one pallet withthe adjoining pallet and allowing pivoting motion in the plane` of theflat surfaces of the pallets, whereby said pallets are joined into aclosed loop with the convex edge of one pallet abutting the concave edgeof an adjoining pallet;

bearing means disposed between each link member,

- at a point intermediate its ends, and the lower surface of the palletto which that link is connected at the center of the pallets convexedge, so that adjacent pallets may pivot with respect to one anotherabout the centers of their convex edges:

means for supporting said pallets on their sides opposite to their flatsurfaces;

means for restraining said pallets` against motion transverse to theircourse;

means for guiding said pallets along a closed loop course; and

means for moving said pallets along said course.

2. The conveyor of claim wherein the means for supporting the palletsconsists of a support member disposed below the pallet and having asurface in abutment with a planar surface of the pallets, with means forproviding a pressurized air iiow through the surface of the supportmember which is in abutment to the surface of the pallets so as tocreate an air flow between them.

3. The conveyor of claim 1 'wherein the means for supporting the palletsconsists of a pair of upright members disposed below the pallets alongopposite side of the conveyor course; flat surfaces at the upper ends ofsaid upright members extending into abutment with coutiguous surfaces onthe pallets; apertures in said flat surfaces; a source of compressedair; and means for directing the compressed air through the apertures soas to create an air bearing surface between the pallets and theuprights.

4. The conveyor of claiml 1 wherein -said concave and convex edges ofthe pallets have an extension downwardly, normal to the fiat uppersurfaces of the pallets `and the link members allow motion of one palletin a direction normal to the flat upper surfaces of the pallets, withrespect to the joining pallets, while retaining the concave yand convexedges of the pallets in abutment to the cornplementary edges ofadjoining pallets.

5. The conveyor of claim 4 wherein means are included for adjusting theeffective lengths of the link members between their points of connectionon two adjoining pallets as a function of the variations between thehorizontal positions of the flat upper surfaces of the adjoiningpallets.

6. The conveyor of claim 5 wherein the means for adjusting the effectivelength of the links between their connecting points on Yadjacent palletsconsists of a track which runs labout the pallet course and cam meanssupported on the link and retained by said track, said track beingseparated by the pallets by a distance which is a function of thehorizontal position of one pallet with respect to adjoining pallets `ateach point on the course.

7. The conveyor of claim 1 wherein said means for supporting saidpallets on their sides opposite to their flat surfaces includes threearms which extend downwardly from the lower sides of the pallets,normally to the at upper surfaces thereof; three tracks which run alongthe pallet course and support the lower ends of the three arms; andmeans for adjusting the effective length of the link members betweentheir connecting points on adjoining pallets as a function of thevariation between the levels of the flat upper surfaces of the adjoiningpallets, as determined by the positions of said three tracks.

References Cited UNITED STATES PATENTS 756,600 4/1904 Dodge 198-108 X1,191,434 7/1916 Keith 198-181 3,185,108 5/1965 Muller 104-25 EDWARD A.SROKA, Primary Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIGN Patent No.3,493,097 Dated February 3, 1970 Inventor-(S) WillS Ford Karr It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 2, line 42, "pellet" should be pallet Column 4, line 64,"inverted" shouldY be inserted Column 5, line l2 "follower" should befollowers line 14, mpu1ses" should be -impulse line 34, "courses" shouldbe course Column 6 line 73, after "claim" insert 1 Column 7, line 7"side" should be Signed and sealed this 22nd day of December 1970.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. WILLIAM E.- SCHUYLER, JR. Attesting OfficerCommissioner of Patents FORM P04050 (1o-69) uscoMM-oc soave-pao .LSGOVEINENT PHINTUIG OFFICE: l... o sl

